Piece of piss (technical term).
Press LHS pedal.
Push gear lever.
When grinding noise stops, release pedal.
Job done.

I do recall being transported on a courtesy bus from Rockwell at Norcross (GA) to Atlanta Apt in a large, manual shift vehicle where the very jolly and friendly lady driver of ethnic origin, made every change (shift) in this way.

It was something of a relief to eventually arrive in time for the flight and allow the mechanically abused nerve endings to relax for a while.

R.